Abigail Sorensen has spent her life trying to unwrap the events of 1990. It was the year she started receiving random chapters from a self-help book called The Guidebook in the post. It was also the year Robert, her brother, disappeared on the eve of her sixteenth birthday. She believes the absurdity of The Guidebook and the mystery of her brother's disappearance must be connected. Now thirty-five, owner of The Happiness Cafe and mother of four-year-old...

Fourteen-year-old Madeleine of Cambridge, England, struggling to cope with poverty and her mother's illness, and fifteen-year-old Elliot of the Kingdom of Cello in a parallel world where colors are villainous and his father is missing, begin exchanging notes through a crack between their worlds and find they can be of great help to each other.